What happened
On September 12, 2017, a Diamond DA42 NG, registration F-HFBS, was on a VFR flight from Cannes Mandelieu to Ghisonaccia. The aircraft was carrying the pilot and three passengers. During the final approach to the Ghisonaccia aerodrome, the aircraft encountered extreme meteorological conditions characterized by strong orographic waves and significant turbulence.
At approximately 14:17 local time, while performing a landing maneuver, the aircraft experienced a sudden loss of control. Radar tracking ceased at 14:17:19, showing the aircraft at an altitude of 1,10 and 500 meters west of the aerodrome. Witnesses reported seeing the aircraft enter a steep dive, descending like a "dead leaf" before impacting a vineyard. The collision resulted in four fatalities and the total destruction of the aircraft.
The investigation
The BEA investigation focused on the aircraft's performance, the pilot's flight planning, and the prevailing weather conditions. Technical examinations of the wreckage confirmed that the landing gear was extended and the engines were functioning normally until impact. However, investigators identified that the aircraft's weight and center of gravity were outside of the permitted flight envelope. Specifically, the takeoff weight from Cannes exceeded the maximum allowable takeoff weight, and the center of gravity was too far aft, which likely compromised the aircraft's stability.
Meteorological analysis revealed the presence of intense orographic waves and wind shear. Satellite imagery and station data from Alistro confirmed strong westerly winds with gusts up to 48 knots, creating highly turbulent conditions and vertical air accelerations near the ground. The investigation also reviewed radio communications, noting that the pilot had been warned by various parties about the deteriorating weather in Corsica prior to the flight.
Findings
- The primary cause of the accident was a sudden stall and loss of control triggered by rapid changes in wind direction and intensity during the approach.
- The aircraft was operating with an aft center of gravity and a weight exceeding the maximum landing weight, which reduced the pilot's ability to recover from the stall.
- The pilot proceeded with the flight despite clear warnings from meteorological services and personal acquaintances regarding the severe turbulence and orographic waves expected in the region.
- The pilot's determination to reach the intended destination, despite the known risks, contributed to the decision to attempt landing in marginal conditions.